In 1231 Frederick forced Henry to promulgate at Worms a _Statutum in favorem principum_, which in 1232 he personally confirmed at a diet at Civitate in Friuli.[30] It was the elaboration and the generalisation of his alliance twelve years earlier with the prelates. ‘Let every prince,’ declared the Emperor, ‘enjoy in peace, according to the approved custom of his land, his immunities, jurisdictions, counties and hundreds, both those which belong to him in full right, and those which have been granted out to him in fief.’ It was a complete recognition of the territorial supremacy of the great nobles, whether churchmen or laymen. No new castle or city was to be set up within their dominions, even by the Emperor. The hundreds men [_centumgravii_] were to act in their name, and no new money was to be struck in any prince’s land that could reduce the currency of his local mintage. The towns and the lesser estates were to be depressed in their favour. The cities were not to exercise jurisdiction outside the circuit of their walls, were not to entertain _Pfahlbürger_, or harbour fugitives or the vassals of any prince. It was a complete renunciation of the earlier policy of the Hohenstaufen. But though powerful in securing the territorial supremacy of the princes, Frederick’s law had little effect in checking the growth of municipal autonomy. The greater cities were already getting rid of their episcopal or baronial lords, and Frederick was quite unable to check the flowing tide. [Sidenote: Persecution of Heresy.] In his shiftless way Henry tried to pose as the champion of the towns and the lesser nobility, that was gradually evolving out of the ancient official class, against the great feudalists whom his father so obstinately favoured. Since Frederick wished to remain for the moment on good terms with the Church, Henry ostentatiously took up an anti-clerical attitude. He had favoured the savage persecutions of heresy which Frederick had allowed Franciscan and Dominican inquisitors to carry out in Germany as well as in Italy (see also chapter xviii.). Conspicuous among them was the Franciscan, Conrad of Marburg, who wandered ‘preaching and teaching’ all over Germany until 1233, when he was assassinated. Henry now sought to end the persecution which he had once favoured. But in 1234 a regular crusade was fought against the Stedinger of the mouths of the Weser, who had refused to pay their tithes. They were easily defeated, and those who escaped massacre abandoned their homes and took shelter in Friesland.